Zinc (Zn) is naturally abundant and vital for life. In contrast, the inhalation of Zn and Zn compounds in dust and fumes can cause severe pulmonary injury and could be incurable (Gonzalez et al., 2011). Metal Fume Fever is the name for an illness caused mainly by overexposure to zinc oxide (ZnO) which is generally from welding, burning or brazing galvanized steel (Zno, 2002). The main cause of this exposure is usually inhalation of the fumes at the workplace/industrial site which leads to acute allergic conditions experienced by many welders/construction workers during their occupational lifetimes (Syed, Ahsan, Lackovic, Katner, & Palermo, 2009). Since galvanized steel is more common in the industry, welders/construction workers having to work in these conditions are more susceptible to the Metal Fume Fever. Other elements such as copper and magnesium may have similar effects.

Zinc oxide fumes cause a flu-like illness called Metal Fume Fever. Symptoms of Metal Fume Fever include headaches, fevers, chills, muscle aches, thirst, nausea, vomiting, chest soreness, fatigue, gastrointestinal pain, and tiredness (Syed et al., 2009). Occupational asthma may also develop as a result due to long-term exposure of zinc oxide. There is little information in the literature regarding the long-term effects or complications of zinc oxide fume exposures. Inhalation of metals can cause acute pulmonary toxicity, chronic fibrosis, or occupational asthma (Wong, Greene, & Robinson, 2012). In the modern industrial world, the most common metals for workers to be exposed to are zinc, aluminum, chromium, nickel, cobalt, vanadium, and platinum.

Usually, these metals come across in the form of oxides or other salts such as sulfides, halides, carbides, or hydrides. The bioavailability of metal salts depends on their solubility (Castro, Kraft, & Frew, 2008). Insoluble compounds will be deposited in the airways and cleared by the mucociliary escalator, whereas soluble salts are more likely to dissolve and enter the lung in the form of ionic metals (Lee, Taneja, & Vassallo, 2012). Workers in metal industries should be made aware of the potential for lung toxicity, including Metal Fume Fever and occupational asthma. In addition, metal salts may cause asthma in people exposed to paint pigments, plastics, or catalysts.

The association of respiratory complications and the workplace has been documented for many centuries. In past centuries, occupational dust exposure was the main concern, leading to fibrosis of the lung and coal worker’s pneumoconiosis (Castro et al., 2008). With improved industrial hygiene and recognition of the employer’s responsibility for the health of the workforce, dust diseases have become less common. Workers with accidental or preexisting asthma were more likely to develop an acute increase in their symptoms when exposed to dust, fumes, or solvents. Occupational asthma symptoms are like those caused by other types of asthma; symptoms may include wheezing, coughing, shortness of breath, chest tightness, runny nose, nasal congestion, eye irritation and tearing.

The diagnosis of Metal Fume Fever can easily be missed because the complaints are non-specific, they resemble several other common illnesses, and the symptom presentation occurs typically 2–4 hours after the exposure (Syed et al., 2009). When respiratory symptoms are showing, Metal Fume Fever may be confused with acute bronchitis or pneumonia. The diagnosis is based primarily on a history of exposure to metal oxide fumes. For the safety and protection of workers, the Occupational Safety and Health Administration (OSHA) has set a legal limit of five milligrams of zinc oxide fume per cubic meter of air (mg/m³) averaged over an 8-hour work shift (Zno, 2002). The National Institute for Occupational Safety and Health (NIOSH) recommends 5 mg/m³ averaged over a work shift up to 10-hours per day, 40-hours per week, with a short-term exposure limit of 10mg/m³ averaged over a 15- minute period (Zno, 2002). The American Conference of Governmental Industrial Hygienists set the time-weighted average of 2 mg/m³ for an 8-hour workday and 40-hour work week (Zno, 2002).

A clinical diagnosis based on a combination of symptoms, metal exposure, exposure time and resolution increase the likelihood of a diagnosis of Metal Fume Fever (Biggs et al., 2016). This is one of the difficult parts of distinguishing symptom because symptoms vary from person to person. Sometimes, white blood cell count goes down and, in some cases, the zinc content is increased in urine and blood (Syed et al., 2009). The symptoms also resemble other normal diseases which increase the difficulty to make a diagnosis through normal physical examination. It is therefore important to verify the patient’s history in the environment of metal oxide, work history, and nature of their job

The best way to prevent Metal Fume Fever is to enforce preventive measures like personal protective equipment (PPE) for workers, a complete implementation of international standards and safety codes for the workforce, with oxygen inhalers and a ventilation system (Biggs et al., 2016). Advance training for workers is also essential as they should be educated properly regarding the reactive nature of chemicals and the extra care they must take while working in a metallic environment, and a chemical examination report (Mulhausen & Damiano, 1998). Most companies do not have a pre-chemical analysis report made before deploying the welding team or in the case of personalized work and the workers are not given any information regarding the chemical content present in the metals which eventually may lead to illness. Serious issues can easily be avoided through a predetermination of chemical agents.

Ventilation during welding is the best way to remove hazardous fumes or oxides from the air (Biggs et al., 2016). Fume particles are smaller than dust and don’t settle easily; to clear the space from their contamination with the breathing air, a mechanized ventilation system would be instrumental. Suspected health effects and occupational exposure may have physical, psychological and emotional effects on workers exposed or potentially affected. An in-depth investigation is needed with the objectives of solving the problem technically and communicating the risk effectively. Risk communication methods are a learned skill and careful thought and planning should be given to how a situation will be communicated from the beginning of the investigation. When addressing the nature of hazardous chemicals and perceptions regarding their use, it is best to assume the low trusts and high concerns may cause people to react emotionally rather than logically.

Investigation Steps

1. Interview everyone that is relevant and record names, dates, times, locations and processes involved.
2. All alleged symptoms and chemical agents in use should be documented.

1. What chemical agents/chemical mixtures and cleaning agents are present?

3. Each worker should be documented about personal protective equipment (PPE) worn. Provide details of specific chemical protective clothing, gloves, eyewear, and respiratory protection.
4. Detail of what exposure controls were in place. Provide descriptions of local use ventilation including, chemical lids, biosafety cabinets, powders weighing lids, engineered lids around equipment.
5. Every possible paths of exposure, including inhalation, skin absorption, ingestion and unintentional contact with mucous membranes after contacting chemicals should be revised.
6. Medical personnel should be hired for any medical issues.

Exposure Assessment, Categorization, Hazard Assessment, & Interpretation Steps

1. A timeline connecting dates and times working with chemical agents to the onset of symptoms for each potential causative agent should be prepared.
2. Identify an exposure categorization scheme.
3. Identify a health effect categorization scheme.
4. Identify health effects based on exposure to substances in question through a review of material safety data sheets (MSDSs), literature review, or other online databases.
5. Discuss characteristics of the substances, especially any new ones, in question with workers that may have been used previously. Determine if any unreported health effects have occurred in this group and if any are reported in works of literature for the substances in question.
6. Discuss the health status of anyone affected with the medical staff.
7. Account for the rate and period of potential exposure along with the relative concentration of all chemical agents involved and the potential absorption for each worker that was affected.

1. Are these factors associated with the symptoms the and the severity of symptoms reported?
2. What individuals remain unaffected that may be in the same area or near the incident area?
3. If so, and how does their exposure differ?

Reaching an Acceptable Conclusion

1. Is there any possibility of a “cause and effect” relationship between the reported/literature health effects, the onset of symptoms, and any potential latency period?
2. It is unlikely to find a perfect scenario where every potential exposure result in the same effect, therefore account for individual inconsistency.
3. Are unintended expectations a factor among individuals with questionable potential exposure?
4. Construct a reasonable explanation to present to the workers who are affected and to the management/supervision.
5. Evaluate who will receive responsibility in the situation. This may require private discussions with senior management prior to more findings. It’s important to anticipate the questions that may come from all parties involved. The trust and credibility of the management involved are likely to be in jeopardy after an incident. How will that trust be rebuilt as the situation is developing?
6. The chances of lawsuits depend on exposures. Confidentiality of all discussions, notes, and written reports must be maintained.

Risk Communication

1. A risk communication meeting should be held with all stakeholders.
2. It is important to use the following risk communication practices when communicating to a group of affected workers and to prepare answers to anticipated questions.

1. It is important to show empathy for those involved. The management may have to apologize by saying sorry.
2. Th group should be allowed as many questions as they wish to ask after introducing the subject.
3. Record questions through means that are visible to the audience, this act shows them that you care, and their issues are heard.
4. Present all prepared remarks and answer questions after the audience has finished voicing their questions and concerns while being fully engaged.
5. Make some simple and positive points while avoiding “scare words” like toxic, cancer, hazardous and negative words like no, never, not, can’t, won’t in relayed messages.
6. A proper response to an unfamiliar question is, “I don’t know, but I will try to find out”. Be sure to revisit the unanswered question later.

3. Summarize the risk communication to document the outcome of any risk communication meetings.

There are several issues that may occur during risk assessment. First, some stakeholders may need training to be able to participate in technical and risk management discussions. Second, some stakeholders may require incentives such as travel funds or lodging at sites of meetings outside the area where they live. Also, it is important to note the level of detail to which exposures are characterized compared to the level of detail of information available in the dose-response assessment, because a lack of corresponding detail in the dose-response assessment can pose a limitation on the interpretation and usefulness of detailed exposure estimates (EPA, 2003).

It is now important to develop control solutions and make decisions after determining the overall health risk based on the exposure. The need for teamwork to review control strategies to ensure a comprehensive risk management solution is key. Demonstrating a working knowledge of prevention about exposure management, hazards, and PPE limits would show an understanding of the impact that occupational strategies possess. When communicating with the stakeholders, it is important to understand the impact of the strategies on business cost, environmental compliance, and ensure adequate resource allocation. Develop a precise mitigation plan that explains the issue and the reason for concern. Finally, share results with the stakeholders to ensure exposures are controlled going forward.

References

• Biggs, J. J., Hughes, M. A., Jolly, A. T., Klees, J. E., Bohnker, B. K., Tee, F., … Hegmann, K. T. (2016). OCCUPATIONAL/WORK-RELATED ASTHMA MEDICAL TREATMENT GUIDELINE Evidence-based Practice Asthma Panel Chairs: Evidence-based Practice Asthma Panel Members. Retrieved from www.mdguidelines.com.
• Castro, M., Kraft, M., & Frew, A. J. (2008). Occupational Asthma. Clinical Asthma, 375–381. https://doi.org/10.1016/B978-032304289-5.10042-6
• Centers for Disease Control and Prevention. (2016). Guidance for the Selection and Use of Personal Protective Equipment (PPE) in Healthcare Settings. Centers for Disease Control and Prevention. Retrieved from https://www.cdc.gov/hai/pdfs/ppe/ppeslides6-29-04.pdf%0A
• EPA. (2003). Framework for Cumulative Risk Assessment. EPA guide. https://doi.org/EPA/630/P-02/001F
• Gonzalez, M., Vignaud, J.-M., Clement-Duchene, C., Luc, A., Wild, P., Bertrand, O., … Paris, C. (2011). Smoking, Occupational Risk Factors, and Bronchial Tumor Location: A Possible Impact for Lung Cancer Computed Tomography Scan Screening. Journal of Thoracic Oncology (Vol. 7). https://doi.org/10.1097/JTO.0b013e318233d7a6
• Lee, J., Taneja, V., & Vassallo, R. (2012). Cigarette smoking and inflammation: cellular and molecular mechanisms. Journal of Dental Research, 91(2), 142–149. https://doi.org/10.1177/0022034511421200
• Mulhausen, J. R., & Damiano, J. (1998). Section 4: Occupational Health 4.1 Occupational Exposure Assessment. Aiha Acgih (Vol. 349). Retrieved from https://www.nps.gov/policy/rm50bsection4.pdf
• Syed, A., Ahsan, M., Lackovic, A., Katner, M. ;, & Palermo, C. (2009). Metal Fume Fever: A Review of the Literature and cases Reported to the Louisiana Poison control center. Journal of the Louisiana State Medical Society (Vol. 161). Retrieved from www.FightTheFluLA.com.
• Wong, A., Greene, S., & Robinson, J. (2012). Metal fume fever – a case review of calls made to the Victorian Poisons Information Centre. Retrieved from http://abs.gov.au/ausstats/abs@.
• Zno, Z. (2002). Safety and Health METAL FUME FEVER. Retrieved from https://www.lincolnelectric.com/assets/us/en/interactive/welding-safety/data/FACT-25.pdf